This contract will provide up-to-date mortality and morbidity information on very low birth weight infants born in 1987 from Missouri. Missouri reflects the total U.S. population in the distribution of racial groups for very low birth weight. It will obtain mortality rates throughout the first year of life for this birth cohort to ascertain whether neonatal mortality has improved at the expense of an increased risk of post-neonatal mortality. By a mailed questionnaire of the study's mothers we will ascertain missing or otherwise unavailable information on prenatal risk status (e.g., smoking or drinking or other lifestyle influences on pregnancy) and on post-neonatal morbidity of infants. Obtain detailed information regarding the hospital environment and transport of sick neonates since one of the more important results of the study may be to provide data on the relation between the "level" of immediate neonatal care available and the subsequent mortality or morbidity of the infant. Results of this type will be of crucial importance to perinatal and infant health care planning.